Process of making friction-facings.



UNTTED @TA. ENT @TWTGE SUMNER SIMPSON, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR T0 RAYBESTOS COMPANY,

- A CORPORATION OF CONNECTICUT.

PROCESS OF MAKING: FRICTION-FACINGS. i

N0 Drawing.

To all whom it may concern:

Be it known that I, SUMNER SIMrsoN, a citizen of the United States, residing in the city of Bridgeport, county of F airfield, and

State of Connecticut, have invented certain new and useful Improvements in Processes of Mak ng Friction-Facings, of whlch the following 1sthe specification.

This invention relates to improvements in process of making friction facings and refers more particularly to the clutch facings and brake linings for motor vehicles and the like.

Among the salient objects of the present invention are to provide a processof mak ing a friction facing from unwoven short felted asbestos fiber, the fiber being united into a compact and uniform mass by means of a comminuted binder; to provide a process of the character referred to in which a uniform Wearing surface is provided formed from short asbestos fiberfto provide a procwhich permits of the use. of a short asbestos fiber, thus utilizing as far as the weaving is concerned a substantially waste product; to provide an improved method of saturating a friction facing and in such a Way as to insure the uniform and complete saturation of the ring by the comminuted binder, and in general to provide an improved process of the character referred to. In the co-pcnding application T have claimed a friction facing made of unwoven felted asbestos fiber, and the present invention relates to the economical process of manufacturing the same. As is well known to those skilled in the art the mine run'of asbestos consists of relatively long fibers and relatively short fibers. -The long fibers are the only portion that can be utilized for spinning and weaving. Heretofore longfiber asbestos has been utilized in the manufacture of woven clutch facings. This woven asbestos friction facing consists essentially of wire covered with asbestos and then woven to form a friction facing. Tn the manufacture of annular friction facing, such as clutch rings, it has been the practice to stamp or cut the ring out in straight strips and then unite the ends by a suitable joint. This has been necessary for the reason that in stamping rings out of the woven sheet the greater part of the sheet would of course be waste. as far as making any further rings are concerned. Inasmuch as the remainder Speeification of Letters Patent.

Patented Apr. as, rare.

Application filed May 22, 191 Serial No. 236,055

of the sheet left after the rings are stamped out can be again re-used to make a new sheet. Describing now the means of carrying out the process, the asbestos fiber is first ground in a suitable crusher or grinding machine and is then put into a heater and mixed with Water or other liquid solution and beateninto a pulp. The pulp is then treated to a further water bath and finally delivered to the paper making machine and formed into laminated sheets of suitable Width and thickness. From there the sheet passes through suitable presses and'driers; Preferably this sheet is of sufficient Width to permit,of four or more friction facings being stamped or cut out of its width. In the manufacture of clutch facings of the ring orannular type they can be easily and readily stamped out of the body of the sheet. This, of course, obviates'the necessity of the jointed ring. The clutch facingsof the cone type can be also formed. Where the endless ring facings are formed it is, of course, apparent-that after they are stamped out of the sheet the larger part of the sheet is left the process as before to form a new batch.

The economy and simplicity of this operation is its chief merit. By this process in time the entire material of the original sheet will finally be formed into clutch rings. No such economy and efliciency of operation can be approximated in the wovenrings if endless unjointed ring facings are vto be formed. After the rings are stamped out or linings, if it is desired to make linings, they are then impregnated or saturated with the desired binder. Various binders are used. However, the question of satisfactorily impregnating or saturating the friction facing has offered practical difficulties.

of the binder to perform its function when once it is thoroughly saturated into the fac-' ing, but in obtaining a sufficient saturation of the facing. The binder may consist of a hard asphalt natural or artificial, mixed with a suitable oil, as a vegetable or a mineral oil, and then this mixture thinned with a suitable vehicle, such as gasolene or benzene. I have further discovered that the manner in which this mixture is made has much more eflicient results are obtained by first mixing the vmelted gilsonite and linseed oil thoroughly together and then adding the gasolene or other vehicle. This produces more efiicient results than Where all three are mixed simultaneously. i/Vhile this manner of mixing the binder seems relatively simple, it tookconsiderable experimenting to ascertain just how this should be done. After the friction members are saturated with the binder, as above stated, they may friction facings may be pressed down to a micrometer thickness.

pended claims.

- I claim as my invention:

1. A process of making friction facings which consists in forming an asbestos facing, mixing a hard bitumen with a suitable oil by melting the bitumen into the oil and then adding to this mixture a volatile vehicle, and finally saturating the facing with a binder formed as above stated.

2. Aprocess of making friction facings which consists in making a friction facing, mixing gilsonite, or the like, with a vegetable oil such as linseed oil, by melting the gilsonite and mixing it with the oil and-then adding to such mixture a, volatile vehicle such as gasolene, and finally impregnating the facing With this binder formed as above stated.

- snmana s narson. 

